Multi-chip millimeter-wave interface

ABSTRACT

Systems and methods are provided for millimeter-wave (MMW) communication, the system includes a transceiver chip to generate and to receive signals. An interface is used to communicate the signals between the transceiver chip and one or more active antenna modules. The signals include modulated MMW signals and control signals. The transceiver chip includes baseband circuitry, up and down conversion mixers, and RF front-end circuitry. An active antenna module receives a first modulated MMW signal from the interface for transmission via antennas and to receive a second modulated MMW signal from the antennas for transmission through the interface to the transceiver chip.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119from U.S. Provisional Patent Application 62/341,027 filed May 24, 2016,which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present description relates generally to integrated circuits, andmore particularly, to multi-chip millimeter-wave interfaces.

BACKGROUND

Millimeter-wave (MMW) electromagnetic radiation corresponds to theextremely-high frequency (EHF), which is designated for the 30 to 300GHz band of the radio-frequency (RF) spectrum. The radio waves in thisband suffer high atmospheric attenuation due to absorption by theatmospheric gasses, and their application is limited to terrestrialcommunication in the kilometer range.

Due to high losses of millimeter-wave signals in interconnects,millimeter-wave front-end blocks have to be placed in close proximity tothe millimeter-wave antennas to limit impact on transmitter output powerand receiver noise figure. Existing solutions transmit modulated signalsat intermediate frequency (IF) that could potentially have severebandwidth limitation due to large fractional bandwidth, especially forhigh throughput applications using channel bonding. The existingtechnology does not allow the use of direct conversion radioarchitecture, which leads to larger die area and requiresnoise-sensitive local oscillator (LO) signal generation and/ormultiplication in a front-end chip. This can complicate implementationof both the chip and the interface architecture.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain features of the subject technology are set forth in the appendedclaims. However, for purpose of explanation, several embodiments of thesubject technology are set forth in the following figures.

FIGS. 1A through 1D illustrate an example of a multi-chipmillimeter-wave (MMW) transceiver system according to aspects of thesubject technology.

FIGS. 2A-2B illustrate an example of a multi-chip master-slave MMWtransceiver system according to aspects of the subject technology.

FIG. 3 illustrates an example of a single-chip MMW transceiver accordingto aspects of the subject technology.

FIG. 4 is a flow diagram illustrating an example of a method forproviding a MMW transceiver according to aspects of the subjecttechnology.

FIG. 5 is a block diagram illustrating an example of an environment, inwhich a MMW transceiver of the subject technology is used.

DETAILED DESCRIPTION

The detailed description set forth below is intended as a description ofvarious configurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The appended drawings are incorporated herein and constitutea part of the detailed description. The detailed description includesspecific details for the purpose of providing a thorough understandingof the subject technology. However, the subject technology is notlimited to the specific details set forth herein and may be practicedwithout one or more of the specific details. In some instances,structures and components are shown in block diagram form in order toavoid obscuring the concepts of the subject technology.

In one or more aspects of the subject technology, systems andconfigurations are described for providing a multi-chip millimeter-waveinterface for sending and receiving modulated signals at the samecarrier frequency as the actual millimeter-wave (MMW) link. The subjecttechnology enables placing different chips at optimal locations in aplatform with minimal die area penalty, while supporting higherbandwidth to enable channel bonding and other systemologies to increaseoverall throughput. The subject solution is scalable to a multi-chiphierarchical phased-array system in which each millimeter-wave port inthe front-end can be connected to either an antenna, or another phasedarray active antenna module. Multiple active antenna modules could beconnected to either enable diversity switching and/or combinedbeam-forming. The MMW interface of the subject technology removes anyrequirement of LO generation and/or multiplication in the front-end ICs.This relaxes noise requirement on the interface and enables simplifiedtransmission of control link and DC power across the interface. Thesubject technology supports various radio architectures includinghomodyne radio architecture, and allows channel boding for increasingthroughput while maintaining all the above-mentioned flexibilities.

FIGS. 1A through 1D illustrate an example of a multi-chip MMWtransceiver system 100 according to aspects of the subject technology.In some implementations, the MMW transceiver system 100, as shown inFIG. 1A, includes a MMW transceiver chip 110, a MMW interface connectingthe MMW transceiver chip 110 to a number of (e.g., N, such as 16 ormore) active antenna modules 150 (e.g., 150-1, 150-2 . . . 150-N). Eachof the active antenna modules 150 is connected to one or more MMWantennas that are capable of transmitting and/or receiving MMW signals156. The MMW transceiver chip 110 can generate and receive signals(e.g., MMW and other signals) from the active antenna modules 150through the MMW interface 130. In some aspects, the MMW interface 130communicates the signals between the transceiver chip 110 and the activeantenna modules 150 without conversion of MMW signals to intermediatefrequency (IF) signals. The communicated signals include modulated MMWsignals and control signals. In some implementations, the communicatedsignals also include clock signals, as described in more details herein.

The MMW transceiver system 100 supports both combined beamforming anddiversity switching modes of operation. In some aspects, some of theactive antenna modules 150 may be combined in a combined beamformingmode to achieve a higher level of beamforming. In one or more aspects,some of the active antenna modules 150 may be used in a in a diversityswitching mode. In diversity switching mode, one or more of the activeantenna modules 150 are active to cover a specific direction, while therest are not active.

The multi-chip MMW transceiver system 100 meets requirements for channelbonding for increasing throughput. The multi-chip MMW transceiver system100 saves on overall die area requirement, is less complex, and has asmaller noise impact because there is no LO frequency generation,multiplication and/or translation in the active antenna modules 150.This also greatly simplifies control link and DC power transmissionacross chips, as there is no noise sensitive frequencygeneration/multiplication/translation in the active antenna modules 150.The control link can be further simplified as the low frequency noiserequirements are relaxed significantly.

In one or more aspects, the transceiver chip 110, as shown in FIG. 1B,includes baseband circuitry including digital baseband 112,analog-to-digital converter (ADC) and digital-to-analog converter (DAC)circuits 114, baseband clock generator 115, and baseband amplifiers 116.The transceiver chip 110 further includes MMW up and down conversionmixers 118, and RF front-end circuitry 120. A voltage-controlledoscillator (VCO) phase-locked loop (PLL) 117 and a MMW in-phase andquadrature-phase (IQ) local oscillator generator (LOGEN) 119 support theMMW up and down conversion mixers 118. The digital baseband 112 includeslogic circuitry, modules, and codes to support physical layer (PHY) andmedia control access (MAC) layers and other baseband functionalities.The baseband clock generator 115 generates clock signals. For example,for the ADC and DAC circuits 114 and the digital baseband 112. TheVCO-PLL 117 can be used by the MMW IQ LOGEN 119 to generate LO signals(e.g., IQ LO signals). In some aspects, the VCO-PLL 117 is used togenerate clock signals for the digital baseband.

The MMW up and down conversion mixers 118 are responsible forup-conversion of the baseband signals to modulated MMW signals withmulti GHz frequencies (e.g., 60 GHz), and for down-conversion of themodulated MMW signals received from the RF front-end circuitry 120. MMWup and down conversion mixers 118 uses IQ LO signals generated by theMMW IQ LOGEN 119 to perform the up and down conversions. This is anadvantageous feature of the subject technology that directly modulatesbaseband signals to generate MMW frequencies for transmission and,contrary to the existing solutions, does not transmit modulated signalsat intermediate frequency (IF). It is understood that transmittingsignal at IF frequencies could potentially have severe bandwidthlimitation especially for high throughput applications using channelbonding, due to large fractional bandwidth. The subject technologyallows the use of direct conversion radio architecture, which leads tosubstantial saving in die area and is not demanding on noise-sensitivityof LO signal generation and/or multiplication in the active antennamodule.

In one or more aspects, RF front-end circuitry (e.g., an active antennamodule) 120 includes a MMW power splitter and combiner 122 and multiplebeamforming channels. The MMW power splitter and combiner 122 is capableof splitting and combining signal power. Hereinafter, the MMW powersplitter and combiner 122 is called the MMW power splitter 122 or theMMW power combiner 122, based on the operational application. Forexample, when the MMW power splitter and combiner 122 is operating as asplitter, it is referred to as MMW power splitter 122. The MMW powersplitter 122 receives the modulated MMW signal generated by the MMW upconversion mixer 118 and splits the modulated MMW signal between thebeamforming channels (e.g., with equal powers). In some aspects, thepowers of the modulated MMW signals received by the beamforming channelsare different. The MMW power combiner 122 further is tasked withcombining modulated MMW signals received from the beamforming channelsto form a single modulated MMW signal for the MMW down conversion mixer118.

The beamforming channels process the modulated MMW signals fortransmission by multiple MMW antennas or for transmission to other chipsas further described herein. Each beamforming channel includes a receive(RX) and a transmit (TX) beamforming channel. The TX beamforming channelincludes a phase shift circuit 124 and a power amplifier (PA) circuit126. The RX beamforming channel includes a low-noise amplifier (LNA)circuit 128 and a similar phase shift circuit 124. Each beamformingchannel is connected to a transmit-receive (TRX) switch circuit 125. TheTRX switch circuit 125 can connect one of the TX or RX beamformingchannels to a multiplexer 127 (e.g., an N-plexer such as a duplexer or afour-plexer). For example, a TX MMW signal from the PA circuit 126 isrouted to the multiplexer 127 and isolated from the LNA circuit 128,whereas a RX MMW signal from the multiplexer 127 is routed to the LNAcircuit 128.

The multiplexer 127 selectively communicates the MMW signals between theMMW transceiver chip 110 and a subsequent circuit or chip (e.g., theactive antenna module 150 of FIG. 1A) or provides one or more controlsignals or DC power supply to the subsequent circuit. The control linkand DC circuit 129 provides control signals and DC bias for provision tothe subsequent circuit or chip. In some aspects, the control link and DCcircuit 129 further provides clock signals for use by the subsequentcircuit or chip. This can be beneficial as the subsequent circuit orchip can use the control signals, clock signals, and/or DC supplyalready existing in the MMW transceiver chip 110 and hence does notrequire separate dedicated power supplies and control signaling at eachactive antenna module. In one or more aspects, the control link and DCcircuit 129 uses clock signals generated by the VCO-PLL 117 or thebaseband clock generator 115.

The active antenna module 150, as shown in FIG. 1C, can be implementedas a separate chip. The active antenna module 150 includes a multiplexer154 (e.g., an N-plexer such as a duplexer or a four-plexer), a controllink and DC circuit 158 and an RF front-end circuit 152. In someaspects, the multiplexer 154 and the control link and DC circuit 158 canbe removed, disabled, or bypassed, in which case the RF front-endcircuit 152 is directly coupled to the MMW transceiver chip 110 of FIG.1B through the interface circuit 130. In one or more aspects, the RFfront-end circuit 152 is similar to the RF front-end circuit 120 of FIG.1B. In some implementations, the active antenna module 150 is similar tothe MMW transceiver chip 110 of FIG. 1B, in which non-used circuitry(e.g., digital baseband 112, ADC and DAC circuits 114 basebandamplifiers 116, MMW direct IQ up and down mixers 118) are disabled,removed, or bypassed. In some aspects, the baseband clock generator 115and VCO-PLL 117 are not disabled and used by the control link and DCcircuit 158. The active antenna module 150 receives a first modulatedMMW signal (e.g., a TX MMW signal) from the interface 130 of FIG. 1A fortransmission via a number of antennas (e.g., 155 of FIG. 1A) andreceives a second modulated MMW signal (e.g., an RX MMW signal) from theantennas for transmission via the interface 130 to the MMW transceiverchip 110.

In one or more implementations, the interface 130, as shown in FIG. 1D,is an MMW interface and includes a coaxial cable 132, a printed circuitboard (PCB), or a flexible PCB. In some aspects, the PCB is the samePCB, on which the MMW transceiver chip 110 and the active antennamodules 150 are mounted. An important feature of the subject technologyis the simplified signaling between the MMW transceiver chip 110 and theactive antenna modules 150 via the interface 130. The signals include amodulated MMW signal 156, a control signal 135, an optional clock signal137, and a DC supply 139, shown in FIG. 1D, on a frequency spectrum. Insome implementations, the control signal 135 is a modulated controlsignal (e.g., at 3 GHz). The low frequency noise requirements in thedisclosed methodology is relaxed as there is no LO frequencygeneration/multiplication or other frequency translation requirements inthe active antenna module. This allows a frequency of the controlchannel of the transceiver chip to be located close to zero frequency(DC) (e.g., Option B in FIG. 1D) or even at DC (e.g., Option C in FIG.1D). The control signal 135 may be used for handshaking or otherpurposes, for example, controlling the phase shifts between two activeantenna module 150 or for controlling gains of variable gain blocks inactive antenna module. In some aspects, the active antenna module 150may use the control signal 135 to generate clock signals. The signalingof the subject solution does not involve frequency generation,translation, or multiplication (e.g., of an LO signal) in the activeantenna module. This makes the disclosed solution significantly simplerand more efficient compared to the existing solutions that have to usesome frequency generation, translation, or multiplication, for example,to provide LO signals for up and down conversion in the active antennamodule. Since the interface 130 does not have to communicate any LOsignals, the low noise requirement of the interface is substantiallyrelaxed. The disclosed architecture is fully scalable from single chipsolution to two chip solution with a separate active antenna module to amultichip tiled solution, in which slave active antenna modules areconnected to one or more masters for combined beamforming or fordiversity switching, as illustrated herein.

FIGS. 2A-2B illustrate an example of a multi-chip master-slave MMWtransceiver system 200 according to aspects of the subject technology.The multi-chip master-slave MMW transceiver system 200 is similar to themulti-chip MMW transceiver system 100 of FIG. 1A, except that one ormore of the active antenna modules 150, for example, 150-2 can be amaster millimeter-wave integrated circuit (MMIC) that can connect tomultiple slave active antenna modules. The master MIMIC (e.g., 150-2)can be connected to one or more slave active antenna modules 170 (e.g.,170-1 . . . 170-M), each of which is coupled to one or more MMWantennas.

As shown in FIG. 2B, the master MIMIC 150-2 is similar to the activeantenna module 150 of FIG. 1C described above. The slave active antennamodule 170 is similar to the master MIMIC 150-2 except that respectiveDC supply and control circuit 158 and multiplexer 154 are removed,disabled, or bypassed. Each of the slave active antenna module 170 iscoupled to a number of MMW antennas that are capable of communicatingmodulated MMW signals 156. The master MIMIC 150-2 can provide controlsignals 135 for use by the slave active antenna module 170. In someaspects, the master active antenna module 150-2 can provide clocksignals for use by the slave active antenna module 170. In some aspects,one or more of the of the slave active antenna module 170 includes theDC supply and control circuit 158 and multiplexer 154, but can beremoved, bypassed or disabled in this mode of operation, and the slaveactive antenna module 170 can use a different bidirectional controlscheme with the master MMIC 150-2, if required as shown in FIG. 2B.

FIG. 3 illustrates an example of a single-chip MMW transceiver 300according to aspects of the subject technology. The single-chip MMWtransceiver 300 is similar to the MMW transceiver chip 110 of FIG. 1Bdescribed above, except that the multiplexer 127 and the control linkand DC circuit 129 are removed, disabled, or bypassed. The single-chipMMW transceiver 300 can be directly coupled to multiple MMW antennas andtransmit and/or receive modulated MMW signals 156. The single-chip MMWtransceiver 300 meets requirements for channel bonding for increasingthroughput. The single-chip MMW transceiver 300 saves on overall diearea requirement and is less complex and has a smaller noise impactsince the chip does not use frequency generation, multiplication and/ortranslation. For example, the single-chip MMW transceiver 300 can berealized on a die with size of about 6 mm². The control link can begreatly simplified as the low frequency noise requirements are relaxedsignificantly. The disclosed interface is thus extremely scalableenabling the same MMIC 1540-2 to be configured to be used from thesingle chip use case (e.g., FIG. 3) to multiple hierarchical tiled modessuch as a two-level mode, as shown in FIGS. 1A and 1B and a three-levelmode, as shown in FIGS. 2A and 2B.

FIG. 4 is a flow diagram illustrating an example of a method 400 forproviding a MMW transceiver according to aspects of the subjecttechnology. The method 400 includes providing a transceiver chip (e.g.,110 of FIGS. 1A and 1B) to generate and to receive signals, thetransceiver chip comprising baseband circuitry (e.g., 112, 114, 115, and116 of FIG. 1B), up and down conversion mixers (e.g., 118 of FIG. 1B),and RF front-end circuitry (e.g., 120 of FIG. 1B) (410). One or moreactive antenna modules (e.g., 150 of FIG. 1B) are provided (420). Aninterface (e.g., 130 of FIGS. 1A and 1D) communicates the signalsbetween the transceiver chip and the one or more active antenna modules(430). An active antenna module of the one or more active antennamodules receives a first modulated MMW signal from the interface fortransmission via a number of antennas (e.g., 155 of FIG. 1A) andreceives a second modulated MMW signal (e.g., 156 of FIG. 1A) from theplurality of antennas for transmission through the interface to thetransceiver chip (440). The signals include modulated MMW signals andcontrol signals (e.g., 135 of FIG. 1D).

FIG. 5 is a block diagram illustrating an example of a networkenvironment 500 that a MMW transceiver chip of the subject technology isused. The network environment 500 includes a number of devices includingan access point 510, a mobile phone 520, a tablet 530, a laptop 540, anda desk top computer 510 communicating via a network 560. Examples of thenetwork 560 includes the Internet, a wireless local area network (WLAN),a wide area network (WAN), a virtual private network (VPN), a home areanetwork, or other networks. The mobile phone 520 may be in communicationwith a number of other mobile devices such as mobile phones 580 and 590through a cellular network supported by a base station 570. In someaspects, any of the devices of the network environment 500 and/or thebase station 570 may include a multi-chip MMW transceiver (e.g., 100 ofFIG. 1A) or a single-chip MMW transceiver (e.g., 300 of FIG. 3) of thesubject technology. The use of disclosed multi-chip MMW transceiver orthe single-chip MMW transceiver in, for example, the base station 570,allows the base station 570 to benefit from a number of advantageousfeatures of the subject technology. For example, the subject technologyenables placing different chips at optimal locations in a platform withminimal die area penalty, while supporting higher bandwidth to enablechannel bonding and other systemologies to increase overall throughput.The MMW interface of the subject technology removes any requirement ofLO generation and/or multiplication in the front-end ICs. This relaxesnoise requirement on the interface and enables simplified transmissionof control link and DC power across the interface.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. Pronouns in themasculine (e.g., his) include the feminine and neuter gender (e.g., herand its) and vice versa. Headings and subheadings, if any, are used forconvenience only and do not limit the subject disclosure.

The predicate words “configured to”, “operable to”, and “programmed to”do not imply any particular tangible or intangible modification of asubject, but, rather, are intended to be used interchangeably. Forexample, a processor configured to monitor and control an operation or acomponent may also mean the processor being programmed to monitor andcontrol the operation or the processor being operable to monitor andcontrol the operation. Likewise, a processor configured to execute codecan be construed as a processor programmed to execute code or operableto execute code.

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations. Aphrase such as an aspect may refer to one or more aspects and viceversa. A phrase such as a “configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A phrase such as a configuration mayrefer to one or more configurations and vice versa.

The word “example” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “example” is notnecessarily to be construed as preferred or advantageous over otheraspects or designs.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. §112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.” Furthermore, to the extent that the term “include,” “have,” or thelike is used in the description or the claims, such term is intended tobe inclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

What is claimed is:
 1. A millimeter-wave (MMW) transceiver system, thesystem comprising: a transceiver chip configured to generate and toreceive signals; and an interface configured to communicate the signalsbetween the transceiver chip and one or more active antenna modules;wherein: the signals comprise modulated MMW signals and control signals,the transceiver chip comprises baseband circuitry, up and downconversion mixers, and RF front-end circuitry, and an active antennamodule of the one or more active antenna modules is configured toreceive a first modulated MMW signal from the interface for transmissionvia a plurality of antennas and to receive a second modulated MMW signalfrom the plurality of antennas for transmission through the interface tothe transceiver chip.
 2. The system of claim 1, wherein the interfacecomprises an MMW interface including a coaxial cable, a printed circuitboard (PCB), or a flexible PCB.
 3. The system of claim 1, wherein thetransceiver chip further comprises a DC supply and control circuitconfigured to handle DC supply and control signals communicated betweenthe transceiver chip and the interface, and wherein a frequency of acontrol channel of the transceiver chip is a near-zero frequency.
 4. Thesystem of claim 3, wherein the active antenna module is similar to thetransceiver chip except that respective baseband circuitry and up anddown conversion mixers of the active antenna module are removed,disabled, or bypassed.
 5. The system of claim 3, wherein the activeantenna module comprises a master millimeter-wave integrated circuit(MIMIC) followed by a plurality of slave active antenna modules, whereinthe interface is scalable and allows the master MMIC to be used inmultiple hierarchical tiled modes.
 6. The system of claim 5, wherein aslave active antenna module of the plurality of slave active antennamodules is similar to the master MIMIC except that a respective DCsupply and control circuit of the slave active antenna module isoptionally disabled.
 7. The system of claim 6, wherein the master MIMICis configured to provide control signals for the salve active antennamodule.
 8. The system of claim 1, wherein the signals further compriseclock signals.
 9. A method of providing a millimeter-wave (MMW)transceiver system, the method comprising: providing a transceiver chipto generate and to receive signals, the transceiver chip comprisingbaseband circuitry, up and down conversion mixers, and RF front-endcircuitry; providing one or more active antenna modules; configuring aninterface to communicate the signals between the transceiver chip andthe one or more active antenna modules; and configuring an activeantenna module of the one or more active antenna modules to receive afirst modulated MMW signal from the interface for transmission via aplurality of antennas and to receive a second modulated MMW signal fromthe plurality of antennas for transmission through the interface to thetransceiver chip, wherein the signals comprise modulated MMW signals andcontrol signals.
 10. The method of claim 9, wherein configuring theinterface comprises configuring an MMW interface including a coaxialcable, a printed circuit board (PCB), or a flexible PCB.
 11. The methodof claim 9, wherein providing the transceiver chip further comprisesproviding a DC supply and control circuit to handle DC supply andcontrol signals communicated between the transceiver chip and theinterface.
 12. The method of claim 11, wherein providing one or moreactive antenna modules comprises providing one or more transceiverchips, after removing, disabling, or bypassing respective basebandcircuitry and up and down conversion mixers of the one or moretransceiver chips.
 13. The method of claim 11, wherein providing theactive antenna module comprises providing a master MMIC followed by aplurality of slave active antenna modules.
 14. The method of claim 13,wherein providing a slave active antenna module of the plurality ofslave active antenna modules comprises providing the master activeantenna module from which a respective DC supply and control circuit isoptionally disabled.
 15. The method of claim 14, further comprisingconfiguring the master MIMIC to provide control signals for the salveactive antenna module.
 16. The method of claim 9, wherein the signalsfurther comprise clock signals.
 17. A semiconductor chip comprising: aplurality of millimeter-wave (MMW) antennas; and MMW transceivercircuitry comprising: an active antenna circuit coupled to the pluralityof MMW antennas; MMW direct conversion mixers coupled to the activeantenna circuit; and a baseband circuit configured to generate transmit(TX) baseband signals for direct up-conversion by the MMW directconversion mixers and to process receive (RX) baseband signals receivedfrom the MMW direct conversion mixers.
 18. The semiconductor chip ofclaim 17, wherein the active antenna circuit comprises a MMW powersplitter and combiner, a plurality of phase shifter circuits, aplurality of MMW low-noise amplifiers (LNAs), a plurality of MMW poweramplifiers, and a plurality of switch circuits.
 19. The semiconductorchip of claim 18, wherein the MMW power splitter circuit is configuredto split an MMW TX signal received from the MMW up conversion mixers forprocessing by the active antenna circuit and transmission by theplurality of MMW antennas, and to combine a plurality of MMW RX signalsreceived from the plurality of MMW antennas and processed by theplurality of MMW LNAs and the plurality of phase shifter circuits. 20.The semiconductor chip of claim 17, wherein the MMW direct conversionmixers comprise MMW direct in-phase and quadrature (IQ) up and downconversion mixers, and wherein the TX baseband signals and RX basebandsignals comprise IQ signals.